Method of plating tubes, &amp;c.



W. H. WINSLOW.

METHOD 0I' PLATING TUBES, &u. APPLICATION FILED FEB. e, 190s.

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ivi-TED sanrns ATNT . WILLIAM HERMAN WINSLOW, F GI-IICG, ILLINOIS.

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Specification of Letters Patent.l

Application led February 6, 1908. Serial No. 414,505.

To all whom 'it may concern:

Be it known that I, WILLIAM HERMAN i WrNsLow, a citizen of the United States, re-

siding at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Methods of Plating Tubes, &c., of which the following is a full, clear, concise, and exact description, reference being had to the accompany ing drawings, forming a part of this specification. Y

My invention relates to an improved process for electroplating' metallic tubes,. etc.,

and has for its object to deposit upon Vsteel or iron tubingl and similar articles a more uniform electrodeposit than has been accomplished in the past, and also to deposit lili this plating in such a manner that the adhesion between it andthe article plated shall be `much 'stronger 'thanI has heretofore been accomplished.

My .invention is particularlyv applicable toconstructing tubes for small boilers, such as automobile boilers, in order to produce a 4tube that shall at once be strong enough to stand the tensional strains and yet be so vthoroughly protected by the plating as to not be subject to the corrosive action of the water and cleaning compounds used in the boiler. Since copper has been found to -answer admirably as a metal for use in this connection, I practically limitmyself to the- "strength to replace. the stay bolts heretofore" used in conjunction with copper tubes, and atthe same time Il have produced a tube much stronger and stider .to resist accidental deformation as well as `being proofag'ain'st corrosion.

4 'Ihe several drawings illustrating my in yvention are as follows: -v

Figure l is a longitudinal section through l a length of tubing before itis plated; Fig.

2 is a view similar to that shown in I? ll,

in which the tube. is slightly countersunk a5 eaclrend; Fig. 3 is a longitudinal section of `the tube shown in F ig. 2 in which vthe tube is arranged ready for'plating; Fig. i is a Vlongitudinal sectional view through the cen ter of the platlng tank, and shows the tube in place in the plating solution, aswell as diagrainmatically the electrical connections usedfor the plating process.

Referrino to the drawings, in my process a tube 1 of suitable material, as soft steel, is first cut t0 the length to be used, as shown in Fig. 1.4 Then it is slightly countcrsunk at-the ends, as shown at 2, 2; then plugs 3, 3 of wood-or similar material are tightly driven into the ends of the tube 1 .but before Eton.

ratenteu iuar. i, aero.

being driven in, conductors' 4.- are inserted in the center of these tubes `and folded over on the inner ends, as shown at 5, 5 so as to make contact with the inside of the tube. The plugs aredriven in suciently to carry the inner ends of the conductors 4 well within the inner corners ofthe conntersinks at the ends of the tube. In'this condition the tubeis subjected to a thorough sand blasting, whichfresults in completely removing all of the scale and oxid from the outside of the tube and leaving exposed the pure iron or steel. rll`he edect of thesand blasting is also to leave'the surface of the tube `in a 'slightly roughened condition. Immediately after' the tubeis cleaned by means of the sand blast, it is lat once dipped into a dilute solution of copper" sulfate, with the result that a thin lm of copper is immediately deposited upon the clean surface by chem-` ical action, and this lilm is of sufficient thickness to protect the tube from'oxidation in the airand permit it to be removed tothe next. plating operation. If it werenot for 'dipping in the copper sulfate solution, even in theshort time elapsing between the sand blasting operation and placing the tube in.

the platingtank, slight-oxidation would oc- .cur which would prevent securing intimate contactV between the plating and the tube.

lAlfter removing from the dilute copper sulfate solution, the tube is nent placed' in an alkaline plating solution, in which the confI ditions are as illustrated in Fig 4.- The tube is suspended inthe solution contained.`

matei'n the tank 6, preferably of insulatine its rial and'containi'ng in the' bottom the cop-l i per .electroded Connection is made by wire` from the electrode 9 to a generator 11 and therethrough to a resistance 13, regulating any oint desired,

switch 12, and thence by wires 14, 14 to the conductors 4, 4 contained within the plugs 3,3. The tube is subjected to the plating action in this alkaline solution for a suincient length of time to deposit a copper coat thick enough to withstand the corrosive action of the acid to be subsequently used in the acid plating bath. It is impracticable to attain any great thickness of coat in the alkaline bath, and in this -process the alkalinebath is used as a supplemental process to the dipping in the copper sulfate solution to completely protect the steel or iron of the tube from the attack of the acid contained'in thel acid plating bath.- After a 4satisfactory coati-nv has been deposited in the alkaline bath, t e tube is removed to an acid plating bath which is substantially the,

same as that shown in Fig. 4, the only difference in ing the nature of the solution. The deposit yof the copper upon the tube continues rapidly inthe acid bath and can be carried to n racticalily, as a result of whic a considera le coating 7 is formed aroundthe tube 1, and this coating 7 extends as shown at 8, 8 around the ends of the tube' and into the countersunk portions, from which it isapparent that by my process I h ave provided-a means for plating the outslde of the tube and also the ends of the tube with a uniform coating of considerable thickness, at the same operation.

The advantages of the tubes made by my process are many, as have been described above, and in this connection I wish to oint away with in my process, since the out that the usual uneven deposit pro uced '-at the point of juncture of the conducting wlres to the article plated is entirely done t point of electrical contact is entirely within the tube and there are no uneven distribution paths between the surface of the tube and 'the electrode, as a result ofwhich the deposit lupon thev tube is evenly distributed over its entire surface.

o lished, although y ing and polishing ing so finishe 'against the chance attack of the steel of the tubes through occasional imperfections; 2nd, the smoot surface of the tubes permits the water in inholes or .the boiler to circulate more readily, and

Since the space between the tubes is often small in actual practice, this factor forms a large part of the boiler eiiiciency. The

desirable in some cases to (p -pinholes in the plating an the alkalineand acid baths be-v polished.

polished surface also assists in theconduc' tion of the heat of the tubes to the water in the boiler.

After depositing upon the tubes the desired thickness of copper plating, I'nd it rovlde against resulting a1- vanic action at these points when the tu es are in use, by covering the tubes Witha thin coating of solder. This I accomplish by dipping the tubes into suitable iiux'and then dipping them in apreferably Warm condition into a melted bath of solder, which may consist of tin or an alloy of tin and lead, or of tin, lead and zinc in suitable proportions. By this means I Afind an even coating of solder is applied that perfectly covers any, slight imperfections in the plating that might have resulted from the presence of dust or dirt on the tubes during plating. v

While I have shown my invention 1n the particular embodiment above described, I do not, however, limit myself to this modification, but wish to claim any e uivalent process for producing the 'results I ave described above. v

What I claim is:

1.'The method of plating tubes, etc., which consists in first preparing the tubes by closing the ends with non-conductlng closing members provided with conductors leading to the ,inside of the tubes, sand blasting the tubes, dipping the tubes 1n a weak' copper salt solution, copper-plating the tubes electrically in an alkahne plating solution by a circuit closed through such conductors, and then co per-platiner the tubes electrically in an aci -plating solution by a similar circuit.

2. The method of plating tubes, etc., Whichconsists in first preparing the tubes byclosing the ends with non-.conducting closing members rovided with conductors leading to the insi e of the tubes, sand blasting the tubes, dipping the tubes in a weak co per sulfate solution, co perlating the tubes electrically in an alka ine atinfr solution by a circuit closed through such conductors, and then co per-platin the tubes electrically in an aci -platmg so ution by a similar.l circuit. 3. The method of' plating tubes, etc., which consists in first preparing the tubes by plugging the ends with non-conducting plugs containing conductors leading therethrough to the inside 'of the tubes, sand blasting the tubes, di ping the tubes a weak copper sulfate so ution, co per-platmg the tubes electrically in an alka ine latin solution bya circuitI closed throng suc conductors, and then co per-platin the tubes electrically in an aci platmgso ution which consists in snd blasting tbe tubes, In Witnesswhereof, I hereunto subscribe immediately dipping the tubes in a Weak myname this fourth day of February, A. D. l0

cogper ulfate 1olutlon, coplerl-platinlg the- `1908. A

tu es e ectriea y in an a (a ine ating solution, copper plating-the tubes e ectric WILLIAM HERMANWIN'SLOW' ally in an acidlating so1ution,c1eanng the Wltnesses: Y copper surface y means of solder flux, and LEONARD W. NOVANDER, the-n dipping the tubes in a hot solder bath. `ALBERT C. BELL. 

